Fiber-optic-module trays and drawers for fiber-optic equipment

ABSTRACT

A unitary tray for operably supporting a fiber-optic module is disclosed. The tray includes a guide base and guide rails that define a central channel sized to accommodate the fiber-optic module. The fiber-optic module can be slid into a central module position from the back or the front of the tray, and then locked in the central module position. Opposing unitary side guides with slotted channels can be used to form a drawer that holds one or more of the trays. The drawers can be used to form fiber-optic equipment such as an interconnection unit that supports the modules and that allows for conveniently making multiple optical fiber interconnections.

PRIORITY APPLICATION

This is a continuation of U.S. patent application Ser. No. 13/539,683,filed on Jul. 2, 2012, the content of which is relied upon andincorporated herein by reference in its entirety, and the benefit ofpriority under 35 U.S.C. §120 is hereby claimed.

FIELD

The present disclosure relates to fiber-optic modules provided infiber-optic equipment that supports fiber-optic connections, and inparticular to trays and drawers used to support the fiber-optic modulesin the fiber-optic equipment

BACKGROUND

Benefits of optical fiber include extremely wide bandwidth and low noiseoperation. Because of these benefits, optical fiber is increasinglybeing used for a variety of applications, including but not limited tobroadband voice, video, and data transmission. Fiber-optic networksemploying optical fiber are being developed and used to deliver voice,video, and data transmissions to subscribers over both private andpublic networks. These fiber-optic networks often include connectionpoints linking optical fibers to provide “live fiber” from oneconnection point to another connection point. In this regard,fiber-optic equipment is located in data distribution centers or centraloffices to support interconnections. To support these interconnections,fiber-optic equipment is located in data distribution centers or centraloffices.

The fiber-optic equipment is customized based on the needs of theapplication. The fiber-optic equipment is typically included in housingsthat are mounted in equipment racks to optimize use of space. Oneexample of such fiber-optic equipment is a fiber-optic module. Afiber-optic module is designed to provide cable-to-cable fiber-opticconnections and to manage the polarity of fiber-optic cable connections.

A fiber-optic module is typically mounted in a tray that fits within achassis or housing (called an interconnect unit or ICU). The tray isused to form a drawer within the housing, which in turn is mounted in anequipment rack or cabinet. Examples of such a tray, drawer and equipmentrack are disclosed in U.S. Patent Application Publication No.2010/0296790. A technician establishes fiber-optic connections tofiber-optic equipment mounted in the equipment rack by pulling out thedrawer and pushing it back into the housing when the connections arecompleted.

Present-day trays and drawers are made of a fairly large number ofparts, which makes them relatively complex and expensive. Further, thetrays and drawers would benefit from configurations that betterfacilitate the insertion and alignment of the fiber-optic modules, aswell as technician access to the modules so that the fiber-opticconnections (e.g., jumper connections and trunk connections) can be morequickly made.

SUMMARY

An aspect of the disclosure is a unitary tray for operably supporting afiber-optic module. The tray includes a base and guide rails that definea central channel sized to accommodate the fiber-optic module. Thefiber-optic module can be slid into a central module position from theback or from the front of the tray, and then locked in the centralmodule position. Unitary side guides with slotted channels can be usedto form a drawer that holds one or more of the trays. The edges of thetrays slidingly engage the slotted channels of opposing side guides.Flexures on the tray edges can be used to engage respective slots in theside guide channels so that the tray can have different tray positions(e.g., front, center and back) relative to the side guides. The drawerscan be used to form fiber-optic equipment such as an interconnectionunit that supports the modules and that allows for making multipleoptical fiber interconnections. The tray as well as the side guides canbe formed by a molding process, which greatly simplifies the fabricationof the trays and side guides.

Another aspect of the disclosure is a unitary tray for operablysupporting a fiber-optic module that has a central axis and alignmentrails. The tray has a base having front and back ends and oppositeedges. The tray also includes parallel guide rails adjacent the edgesthat define a central open channel sized to accommodate the fiber-opticmodule. The tray further includes front and back insertion guidesrespectively formed in the parallel guide rails and configured toreceive, support and align the fiber-optic module within the centralopen channel. The tray additionally has central guiding features formedon opposing inside surfaces of the parallel guide rails between thefront and back insertion guides. The central guiding features areconfigured to receive the fiber-optic module and guide the fiber-opticmodule to a central module position within the tray. The tray has itsunitary structure by virtue of being formed by molding, i.e., the trayis a molded structure.

Another aspect of the disclosure is a drawer for fiber-optic equipmentthat includes the tray as described above, and first and second opposingunitary side guides configured to slidingly engage the edges of thetray. In an example, the sides guides are configured so that the traycan be reside in a front tray position, a central tray position or aback tray position relative to the side guides. The tray can be lockedin any of these positions and then unlocked to move the tray to anotherone of the positions.

Another aspect of the disclosure is a tray for operably supporting afiber-optic module that has a central axis and alignment rails. The trayhas a flat and generally rectangular base having front and back ends, atop side, and opposite edges. A pair of substantially parallel guiderails extending upwardly from the base and reside inboard of the edges.The guide rails have front and back ends and inside surfaces thatdefine, along with a central portion of the base, a central open channelhaving a central axis and sized to accommodate the fiber-optic module.Front and back insertion guides are respectively formed in the insidesurfaces of the guide rails adjacent the front and back ends and areconfigured to receive and support the fiber-optic module from the topside. The fiber-optic module alignment is supported so that the centralaxis of the alignment module is substantially aligned with the centralaxis of the central open channel. Central guiding features are formed onthe inside surfaces of the guide rails between the front and backinsertion guides. The central guiding features are configured to receivethe fiber-optic module on the alignment rails from the top side andguide the fiber-optic module to a central position within the tray. Thetray is formed as a unitary structure. In an example, the unitarystructure is formed using a molding process using a single material.

Another aspect of the disclosure is a tray for operably supporting afiber-optic module having alignment rails. The tray includes a flat,rectangular base having front and back ends and opposite edges. Parallelguide rails reside adjacent the edges and define, along with a portionof the base, a central open channel sized to accommodate the fiber-opticmodule. Front and back insertion guides are respectively formed in theinside surfaces of the guide rails adjacent the front and back ends andare configured to receive and support the fiber-optic module alignmentrails and substantially align the central axis of the alignment modulewith the central axis of the central open channel. Slots are formed onopposing inside surfaces of the parallel guide rails between the frontand back insertion guides. The slots run in the axial direction and areconfigured to receive the alignment rails of the fiber-optic module andguide the fiber-optic module to a central module position within thetray.

Another aspect of the disclosure is a drawer for fiber-optic equipmentthat utilizes the tray described above and that further includes firstand second opposing unitary side guides. Each side guide has at leastone channel configured to receive and slidingly engage the tongues ofthe tray and operably engage the respective flexures to releasably lockthe tray a plurality of different tray positions relative to the sideguides.

Additional features and advantages will be set forth in the DetailedDescription which follows, and in part will be readily apparent to thoseskilled in the art from the description or recognized by practicing theembodiments as described in the written description and claims hereof,as well as the appended drawings. It is to be understood that both theforegoing general description and the following Detailed Description aremerely exemplary, and are intended to provide an overview or frameworkto understand the nature and character of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding, and are incorporated in and constitute a part of thisspecification. The drawings illustrate one or more embodiment(s), andtogether with the Detailed Description serve to explain principles andoperation of the various embodiments. As such, the disclosure willbecome more fully understood from the following Detailed Description,taken in conjunction with the accompanying Figures, in which:

FIG. 1A is a front elevated view of an example fiber-optic module;

FIG. 1B is a top-down view of the fiber-optic module;

FIG. 2A is a top elevated view of an example embodiment of a trayaccording to the present disclosure;

FIG. 2B is a bottom elevated view of the tray of FIG. 2A;

FIG. 3A is a close-up view of the center portion of the inside of one ofthe guide rails showing an example guiding feature as well otherlatching features;

FIG. 3B is a close-up view of the center portion of the outside of oneof the guide rails showing an example tray positioning feature;

FIG. 4A is a front elevated view of the tray of FIG. 1 shown with themodule of FIG. 3 disposed in a front position in the tray;

FIG. 4B is similar to FIG. 4A, but with the fiber-optic module disposedin a back position in the tray;

FIG. 4C is similar to FIGS. 4A and 4B, but with the fiber-optic modulelocked in a center position in the tray;

FIG. 5A and FIG. 5B are two elevated views from different sides of anexample side guide used to form a drawer that can slidingly support oneor more trays in multiple positions;

FIG. 6A through 6C are front elevated views of example embodiments of adrawer, showing the two trays operably supporting respective modules inthe center position, and illustrating the front, back and centerpositions of the trays within the drawers;

FIG. 7A is similar to FIG. 6A and additionally shows jumpers and afiber-optic cable operably connected to the fiber-optic modules;

FIG. 7B is similar to FIG. 7A but with the trays in different traypositions within the drawer; and

FIG. 8 is a front elevated view of example fiber-optic equipment in theform of an interconnection unit (ICU) that houses the drawers and thefiber-optic modules supported by the trays.

DETAILED DESCRIPTION

Reference is now made in detail to various embodiments of thedisclosure, examples of which are illustrated in the accompanyingdrawings. Whenever possible, the same or like reference numbers andsymbols are used throughout the drawings to refer to the same or likeparts. The drawings are not necessarily to scale, and one skilled in theart will recognize where the drawings have been simplified to illustratethe key aspects of the disclosure.

The claims as set forth below are incorporated into and constitute partof this Detailed Description.

The entire disclosure of any publication or patent document mentionedherein is incorporated by reference.

Cartesian coordinates are shown in some of the Figures for the sake ofreference and are not intended to be limiting as to direction ororientation.

Fiber-Optic Module

FIG. 1A is an elevated view of an example fiber-optic module (“module”)10 for use with a tray 100, while FIG. 1B is a top-down view. An examplemodule 10 is disclosed in U.S. Pat. No. 6,758,600. The module 10 isgenerally rectangular and has a central axis A1. The module 10 includesa front end 14, a back end 18, generally flat top and bottom sides 24and 28, and edges 30. The edges 30 each include an alignment rail 32having front and back ends 34 and 38. The alignment rails 32 rungenerally in the z-direction.

The front end 14 includes a number of adapters 40 where jumper cables(“jumpers”) 44 can be connected. The adapters 40 are shown by way ofexample as being configured to accept LC fiber-optic connectors.However, adapters 40 can be configured for any fiber-optic connectiontype desired.

A lever 50 with an outside edge 52 is operably connected to back end 38of one of alignment rails 32. The lever 50 includes a latch 54 on itsoutside edge 52. To facilitate moving lever 50 inward toward module 10,a finger hook 56 is provided adjacent the lever at module back end 18 sothat a technician can use two fingers to squeeze the lever toward thefinger hook.

The module 10 also includes at back end 18 an adapter 60 configured toconnect to multiple optical fibers. An example adapter 60 is amulti-fiber adapter such as an MTP fiber-optic adapter configured toestablish connections to multiple optical fibers (e.g., twelve (12)optical fibers) of an optical fiber cable 62 having a multi-fiberconnector 64, such as an MTP connector. The module 10 may be configuredto manage the polarity between the front-side adapters 40 and theback-side adapter 60.

Tray

FIG. 2A is a front elevated view of an exemplary embodiment of tray 100according to the disclosure, while FIG. 2B is a bottom elevated view ofthe tray. The tray 100 is generally rectangular in shape and includes afront end 114, a back end 118, a top side 124, a bottom side 128, andopposite edges 130. The tray 100 also includes a generally flatrectangular base 134. The base 134 includes frontward and backward(i.e., rearward) access openings 136 and 138, as well as a U-shapedrecess 140 at front end 114. In an example, base 134 is relatively thin,i.e., has a thickness TH in the range from about 0.060 inches to about0.125 inches.

The tray 100 is configured to accommodate one fiber-optic module 10 ineither a front module position FMP, a center module position CMP or aback module position BMP, as shown and discussed in greater detailbelow.

The tray 100 further includes a pair of generally parallel guide rails150 that run longitudinally and that arise from the base. Guide rails150 reside adjacent and inboard from respective edges 130. The guiderails 150 have respective inside surfaces 151 that, along with a centralportion of base 134, define a central open channel 152 having a centralaxis A2.

The guide rails 150 include opposing front insertion guides 154 formedon inside surfaces 151 adjacent front end 114. The guide rails 150 alsoinclude opposing back insertion guides 158 formed on inside surfaces 151adjacent back end 118. In an example, front and back insertion guides154 and 158 are defined by respective front ledges 155 and back ledges159 formed in the respective inner surfaces 151 of guide rails 150. Theledges 155 and 159 are configured to support alignment rails 32 onmodule 10.

The front and back insertion guides 154 and 158 on guide rails 150 areseparated in the axial direction by a central guiding feature 166. FIG.3A is a close-up view of the center portion of inside surface 151 of oneof guide rails 150 and illustrates an example central guiding feature166 in the form of top and bottom corrugations 168T and 168B. The topand bottom corrugations 168T and 168B are spaced apart in the verticaldirection (i.e., the Y-direction) and are offset relative to each otherin the horizontal direction (i.e., the Z-direction). The top and bottomcorrugations 168T and 168B define a horizontal guide slot 170. Theoffset configuration of top and bottom corrugations 168T and 168B isused to accommodate features in a mold used when forming tray 100 by amolding process. In another example embodiment, guide slot 170 iscontinuous. The back insertion guides 158 each include a vertical edge157 adjacent central guiding feature 166 that is configured to engagelatch 54 of module 10 as discussed below.

With reference again to FIG. 2A, guide rails 150 each include at frontend 114 front pull tabs 190 and jumper guides 194. Jumper guides 194 areconfigured to guide jumper cables 44, as discussed below in connectionwith FIGS. 7A and 7B. A centrally located back pull tap 196 is attachedto base 134 at back end 118.

Guide rails 150 and edges 130 define tongues 200 formed by the portionof base 134 adjacent each of the edges. The tongues 200 each include apositioning feature 206. FIG. 3B is a close-up view of the centerportion of outside of one of guide rails 150 showing an example traypositioning feature 206. In the example of FIG. 3B, positioning feature206 is configured as a flexure by providing a relatively thin andelongated aperture 210 that defines a flexible wall 212 at edge 130. Inan example embodiment, flexible wall 212 includes a front-positiondetent 216F, a back-position detent 216B and a locking detent 216L thatresides about midway between the front-position and back-positiondetents. The flexibility of a flexure type of positioning feature 206allows for the positioning feature to be flexed to disengage thepositioning feature (including the detents formed thereon) from itscomplementary locking feature, as discussed below.

With reference to FIG. 3A and FIG. 3B, tray 100 also includes a modulelocking feature 220 along one of guide rails 150 in between front endguide 154 and central guiding feature 166. The module locking feature220 is configured to lock module 10 in the center position of tray 100as described below. The module locking feature 220 includes a lever 222flexibly connected at its backward end to an end portion of centralguiding feature 166 and connected at its frontward end to a downwardlydepending latching feature 224 that engages the front end 34 of modulealignment rail 32 to lock module 10 in a center position of tray 100, asdescribed below.

The tray 100 has a length L and a width W, which in an example are about11 inches and 4.5 inches, respectively. Other sizes for tray 100 arepossible, with the size being largely dependent upon on the size of theparticular modules 10 being supported by the tray.

In an example embodiment, tray 100 is formed as a unitary structure. Inan example, the unitary embodiment of tray 100 is formed by molding asingle material. An example material for tray 100 is plastic.

Module Positions in Tray

FIGS. 4A through 4C are similar to FIG. 2A, except that theyrespectively show module 10 disposed in a front module position FMP, aback module position BMP and a center module position CMP. The front andback module positions FMP and BMP are temporary positions used to insertand lock module 10 in the center module position CMP.

With reference to FIG. 4A, module 10 can be disposed in tray 100 atfront module position FMP as shown in FIG. 4A by aligning the modulewith tray front end 114 so that module central axis A1 and tray centralaxis A2 are substantially aligned in the Y-Z plane, with the module justabove the tray at the tray front end. The module 10 can then be loweredonto (i.e., dropped into) tray 100 at front end 114 to initiateengagement of alignment rails 32 with the front end guides 154, with thealignment rails resting on ledges 155. The module 10 can then be slidinto the center module position CMP as shown in FIG. 4C by urging themodule in the +Z direction. At this point, alignment rails 32 engagecentral guide 166, i.e., they travel within guide slot 170 until latch54 of lever 50 engages edge 157 of back insertion guides 158 to preventfurther backward motion. The latch 54 is inwardly biased such thatmodule 10 can be installed in tray 100 from either front end 114 or backend 118.

At this point, locking feature 220, which is normally in the latchposition, has secured module 10 in the center module position. Torelease module 10 locking feature 220 must be depressed and the moduleslid forward. To disengage (unlock) module 10, a technician can inserttheir fingers through back opening 138 to access lever 50 and fingerhook 56 and disengage latch 54. The technician can also disengagelocking feature 220 by pushing down lever 222 of the locking feature.This allows module 10 to slide within guide slots 170 either axiallyforward or backward within tray 100. When moving module 10 to frontmodule position FMP or back module position BMP, alignment rails 32 ofthe module transition from being guided by guide slots 170 to resting onfront or back ledges 155 or 159. This allows module 10 to be easilylifted up and out of tray 100 when in front module position FMP or backmodule position BMP.

The tray 100 is configured so that module 10 can be placed directly inback module position BMP in essentially the same manner as it is placedin front module position FMP (including with module front end 14 facingtray front end 114). The module 10 is then moved in the −Z directioninto center module position CMP. With reference to FIG. 4B, this isaccomplished by disposing module 10 so that its axis A1 and tray axis A2are substantially aligned in the Y-Z plane with the module just abovethe tray at the tray back end 118. The module 10 is then lowered(dropped) into place so that alignment rails 32 of the module rest onledges 159 of back insertion guides 158. The module 10 is then urged inthe −Z direction so that alignment rails 32 engage central guide 166,i.e., they travel within guide slot 170 until latch 54 of lever 50engages edge 157 of back insertion guides 158 to prevent furtherbackward motion. The module 10 is then locked into central moduleposition CMP using locking feature 220 as described above.

Drawers with Movable Trays

An aspect of the disclosure is a drawer that operably supports one ormore trays 100 as described above. FIG. 5A and FIG. 5B are two elevatedviews of different sides of an example side guide 320, wherein two suchside guides are used to form a drawer 400, as shown in the elevatedviews of FIGS. 6A through 6C. The drawer 400 is configured so that eachtray 100 supported thereby can be placed in a front tray position FTP(FIG. 6A), a center tray position CTP (FIG. 6C) and a back tray positionBTP (FIG. 6B) and releasably locked in these positions.

The side guide 320 includes a front end 324, a back end 328, an innerside 332 and an outer side 334. The side guide 320 includes one or moreopen channels 340, with each channel sized to accommodate and supporttongues 200 of tray 100. Two channels 340 are shown by way of exampleand are used to form example drawer 400 that supports two trays 100, asshown in FIGS. 6A through 6C. Thus, drawer 400 is formed by arrangingtwo side guides 320 with their inner sides 332 facing each other andspaced apart so that one or more trays 100 can fit between the sideguides with tongues 200 sliding in the corresponding side-guide channels340.

As best seen in FIG. 5B, side guide 320 includes, in each channel 340,front, center and back slots 350F, 350C and 350B, with each slotconfigured to engage with positioning feature 206 formed on tongue 200,depending on the position of tray 100 relative to the side guide. Forexample, in FIG. 6A, the top tray 100 is in front tray position FTPrelative to side guides 320, with tray positioning features 206 engagingfront slots 350F. Likewise, in FIG. 6C, the bottom tray 100 is in centerposition CTP relative to side guides 320, with tray positioning features206 engaging center slots 350C.

FIG. 6A shows drawer 400 with top tray 100 in front tray position FTPrelative to side guides 220, with the tray positioning features 206engaging front slots 350F. FIG. 6B shows the top tray 100 in back trayposition BTP relative to side guides 220, with the tray positioningfeatures 206 engaging back slots 350B. FIG. 6C shows both the top andbottom trays 100 in central tray position CTP relative to side guides220, with their respective tray positioning features 206 engagingrespective central slots 350C.

In an example embodiment, each positioning feature 206 is configured asa flexure having the aforementioned front and back detents 216F and 216Band locking detent 216L. In such an example embodiment, in front trayposition FTP of tray 100 within drawer 400, front detent 216F engagesfront end 324 of side guide 320 and locking detent 216L and back detent216B reside within front slot 350F. This allows the positioning features206 to click into place on the respective side guides 320 and to hold(lock) tray 100 in front tray position FTP. The tray 100 can bedisengaged from being locked in front tray position FTP by a userapplying minimal pressure to flex the positioning feature 206 to releaseit from front slot 350F.

When tray 100 is in center tray position CTP, the entire positioningfeature 206 fits within center slot 350C and is released by urging thetray forward or backward to inwardly flex the positioning feature sothat it disengages from the center slot. The back tray position BTP oftray 100 has essentially the same locking configuration as front trayposition FTP, but with back detents 350B engaged with back ends 328 ofside guides 320.

In an example, side guide 320 is a unitary structure. Further in theexample, side guide 320 is formed by molding. An example material forside guide 320 is plastic.

FIG. 7A is similar to FIG. 6A and shows a number of jumper cables 44attached to adapters 40 at front end 14 of module 10, with the topmodule in center module position CMP in tray 10, and the top tray infront tray position FTP. FIG. 7B is similar to FIG. 6B, but with trays100 in different tray positions within drawer 400. The jumper cables 44are shown as being guided by one of jumper guides 194 and connected tocorresponding adapters 40 on module 10. Likewise, two fiber-optic cables62 with multi-fiber connectors 64 are shown as being connected torespective adapters 60 at back ends 18 of two modules 10. The twofiber-optic cables 62 are shown as entering drawer 400 at back ends 118of trays 100, while the jumper cables 44 enter from tray front end 114.

Fiber-Optic Equipment

FIG. 8 is an elevated and partially cut-away view of fiber-opticequipment shown by way of example as an interconnection unit (ICU)assembly 500. The ICU assembly 500 includes at least one drawer 400,which is shown by way of illustration as operably supporting two modules10, which are shown in center module position CMP in trays 100. Theexemplary ICU assembly 500 may be provided at a data distribution centeror central office to support cable-to-cable fiber-optic connections andto manage a plurality of fiber-optic cable connections.

The ICU assembly 500 includes a fiber-optic equipment housing 510 thathas a front end 514, a back end 518, and an interior 516. The housing510 includes at front end 514 a front door 530 that swings downward toallow access to interior 516. The housing 510 includes front-doorlatches 532 configured to allow front door 530 to be latched in theclosed position and unlatched to open the front door and allow access tohousing interior 516 and drawers 400, trays 100 and modules 10 operablysupported therein. The housing 510 optionally includes a similar backdoor (not shown) at back end 518.

Note that trays 100 can be pulled into front tray position FTP so thatthe trays extend beyond housing front end 514. Further, modules 10operably supported in respective trays 100 can be moved between frontand center module positions FMP and CMP to allow for easy access,servicing, installation and removal of the modules.

The housing 510 is configured so that it can be installed in afiber-optic equipment rack (not shown) if desired. The housing 510 isshown as being 1U-sized, with “U” equaling a standard 1.75 inches inheight, but could be any other U-size desired, or any other heightdesired.

As discussed above, trays 100 can be moved and extended from andretracted back into their drawer 400. Any number of trays 100 can besupported in drawers 400 within housing 510. Likewise, any number ofmodules 10 can be supported in trays 100.

It will be apparent to those skilled in the art that variousmodifications to the preferred embodiments of the disclosure asdescribed herein can be made without departing from the spirit or scopeof the disclosure as defined in the appended claims. Thus, thedisclosure covers the modifications and variations provided they comewithin the scope of the appended claims and the equivalents thereto.

What is claimed is:
 1. A tray for operably supporting a fiber-opticmodule that has a central axis and alignment rails, the tray comprising:a base having front and back ends, a top side and opposite edges;parallel guide rails adjacent the edges that define a central openchannel sized to accommodate the fiber-optic module; front and backinsertion guides respectively formed in the parallel guide rails andconfigured to receive, support and align the fiber-optic module withinthe central open channel; central guiding features formed on opposinginside surfaces of the parallel guide rails between the front and backinsertion guides, the central guiding features being configured toreceive the fiber-optic module and guide the fiber-optic module to acentral module position within the tray; and wherein the tray is formedas a unitary, molded structure from a single piece of material.
 2. Thetray according to claim 1, further comprising a fiber-optic modulelocking feature formed on one of the guide rails and configured tooperably engage a portion of the fiber-optic module to lock the modulein the center module position.
 3. The tray according to claim 1, furthercomprising front and back access openings formed in the base.
 4. Thetray according to claim 1, wherein the front and back insertion guidesare configured so that the fiber-optic module can be lowered onto eitherthe front or back insertion guide from the front side of the base andthen slid into the central module position.
 5. The tray according toclaim 1, further comprising flexures formed on the respective edges ofthe base.
 6. A drawer for fiber-optic equipment, comprising: the tray ofclaim 5; and first and second opposing unitary side guides configured toslidingly engage the edges of the tray.
 7. The drawer according to claim6, wherein each of the side guides includes at least one channel, andwherein the side guides are configured so that the edges of the tray areslidingly engaged by the respective channels of the opposing sideguides.
 8. The drawer according to claim 7, wherein each channelincludes a plurality of slots, and wherein the flexure engages one ofthe slots to define a corresponding plurality of tray positions relativeto the side guides.
 9. The drawer according to claim 7, furthercomprising multiple trays and a housing having an interior that containsthe side guides and the multiple trays.
 10. A tray for operablysupporting a fiber-optic module that has a central axis and alignmentrails, the tray comprising: a flat and generally rectangular base havingfront and back ends, a top side, and opposite edges; a pair ofsubstantially parallel guide rails extending upwardly from the base andresiding inboard of the edges, the guide rails having front and backends and inside surfaces that define, along with a central portion ofthe base, a central open channel having a central axis and sized toaccommodate the fiber-optic module; front and back insertion guidesrespectively formed in the inside surfaces of the guide rails adjacentthe front and back ends and configured to receive and support thefiber-optic module alignment rails and substantially align the centralaxis of the alignment module with the central axis of the central openchannel; central guiding features formed on the inside surfaces of theguide rails between the front and back insertion guides, the centralguiding features being configured to receive the alignment rails of thefiber-optic module and guide the fiber-optic module to a centralposition within the tray; and wherein the tray is formed as a unitarystructure.
 11. The tray according to claim 10, further comprising afiber-optic-module locking feature formed on one of the guide railsbetween the front insertion guide and the central guiding features, thefiber-optic-module locking feature being configured to operably engage aportion of the fiber-optic module to lock the module in a center moduleposition.
 12. The tray according to claim 10, further comprising thefiber-optic module.
 13. The tray according to claim 10, wherein thefront and back insertion guides each include ledges upon which thealignment rails rest when the fiber-optic module is inserted into thetray from the top side at the front end or the back end of the tray,respectively.
 14. The tray according to claim 10, further comprisingtongues formed on the respective edges of the base, the tongues havingformed therein respective flexures.
 15. A drawer for fiber-opticequipment, comprising: the tray of claim 14; and first and secondopposing unitary side guides, each having at least one channelconfigured to receive and slidingly engage the tongues of the tray, witheach channel having front, center and rear slots configured to operablyengage at least a portion of the flexure so that the tray can be lockedin either a front tray position, a center tray position or a back trayposition relative to the side guides and unlocked from a given one ofthe tray positions by flexing the flexure.
 16. The drawer according toclaim 15, wherein each flexure has a front-position detent and arear-position detent, with a locking detent therebetween.
 17. The draweraccording to claim 16, wherein the side guides include multiple channelsand the drawer supports multiple trays.
 18. The drawer according toclaim 17, further comprising the fiber-optic modules operably arrangedone in each of the trays, with each module having a plurality offront-end adapters and a single multi-fiber back end adapter.
 19. Thedrawer of claim 18, further comprising one or more jumpers operablyconnected to the corresponding one or more front-end adapters and amulti-fiber fiber-optic cable operably connected to the back-endmulti-fiber connector.
 20. The drawer of claim 18, further comprising ahousing having an interior that operably supports the drawer to form aninterconnection equipment unit.
 21. A tray for operably supporting afiber-optic module having alignment rails, comprising: a flat,rectangular base having front and back ends, a top side, and oppositeedges; parallel guide rails adjacent the edges that define, along with aportion of the base, a central open channel having a central axis andsized to accommodate the fiber-optic module; front and back insertionguides respectively formed in the parallel guide rails and configured toreceive the fiber-optic module from the top side and support and alignthe fiber-optic module within the central open channel; slots formed onopposing inside surfaces of the parallel guide rails between the frontand back insertion guides, the slots running in the axial direction andbeing configured to receive the alignment rails of the fiber-opticmodule and guide the fiber-optic module to a central module positionwithin the tray.
 22. The tray according to claim 21, wherein each slotis defined by top and bottom offset corrugations.
 23. The tray accordingto claim 21, wherein each edge of the base includes a flexure definedtherein.
 24. The tray of claim 21, further comprising the module.
 25. Adrawer for fiber-optic equipment, comprising: the tray of claim 24; andfirst and second opposing unitary side guides each having at least onechannel configured to receive and slidingly engage the tongues of thetray and to operably engage the respective flexures to releasably lockthe tray a plurality of different tray positions relative to the sideguides.